1. Field of the Invention
This invention relates to the poultry industry, and in particular, infectious bursal disease, a known scourge of this industry. Specifically, a novel virus is identified, and methods of using this virus and information associated therewith are disclosed. A neutralizing monoclonal antibody (Mab) specific for the virus, and a vaccine based thereon, are also disclosed.
2. Background of the Invention
Infectious bursal disease (IBD) has previously been identified as a significant economic drain in the poultry industry. This disease, which strikes chiefly at the chicken industry, is caused by virulent field viruses which cause a highly contagious, immunosuppressive disease condition. This condition, of course, exacerbates other infections in the chicken population. The disease is noted for its impact on young chickens, and is characterized by lesions in the lymphoidal follicles of the bursa of Fabricius.
In U.S. patent application Ser. No. 07/227,311, filed Aug. 2, 1988, the inventor herein reported the identification of a novel IBD virus not neutralized by any available vaccine and not neutralized by antibodies previously developed as sensitive to, and capable of neutralizing, all known viruses identified as inducing IBD. The entire disclosure of that application is incorporated herein by reference. Indeed, that application reports the deposition, under Budapest Treaty Conditions, of two viruses, at the Institute Pasteur, under accession numbers i-792 and i-793. This virus, now referred to as GLS, was detected by the use of monoclonal antibodies, particularly those identified as R63 and B69, expressed by hybridoma cell lines deposited under ATCC HB-9437 and HB-9490. These Mab's, identified as neutralizing monoclonal antibodies, comprise a passive vaccine against known strains of viruses inducing IBD and act as a means for detecting the presence of GLS virus, since the positive binding by a non-neutralizing antibody, such as B29, coupled with a negative reaction for R63 and B69 is proof of the GLS IBDV presence.
Thus, recent history in the poultry industry, particularly that along the eastern coast of the United States, reflects an increasingly large number of reports of outbreaks of infectious bursal disease, which are not fully prevented by any of the known vaccines, including those prepared from the monoclonal antibodies discussed above. Due to the severe economic strain placed on the poultry industry by these uncontrolled outbreaks, a significant degree of investigation of the cause of the outbreaks, and the reason for the failure of known vaccines to prevent such outbreaks, has been undertaken. No fault has been detected in the preparation of the vaccines, or their administration. Nonetheless, unchecked outbreaks continue to occur.
This continual outbreak is addressed, in part, by a vaccine developed using the virus addressed in U.S. application Ser. No. 07/227,311. This vaccine (GLS vaccine), now being successfully commercially introduced, alone or together with more conventional vaccines, provides protection against the dominant forms of IBDV infections.
New research, using monoclonal antibodies specific to 3 general categories of IBDV, has provided greater understanding of the IBDV. These developments are reported in the application identified above, U.S. application Ser. No. 07/432,752.
That application reports the development of neutralizing Mabs such as 179 and 8, available at the ATCC under deposit numbers HB-10158, HB-10174, and neutralizing against all previously known IBDV, and 57, ATCC deposit number HB-10156, neutralizing and specific to the GLS strain and variants. Recently research has identified yet a new IBDV in the field, not controlled by the GLS-vaccine. Monoclonal antibody 179 does not even react in vitro.
Thus, there is yet a new IBDV in the field, against which there is no current active vaccine, and against which no passive vaccine has yet been provided. This new virus, apparently a GLS variant and mutation thereof, given the Mab 57 in vitro binding, is currently uncontrolled. Protection for the poultry industry against this new IBDV is therefore a pressing need.